Hello!  Im currently working with Processing for my independent class for college and Im working with some big codes.  Currently it creates these tentacles things and places them on the right side.  Im trying to make it so it borders all around the screen and i want to add an ameba type organism in the middle that moves around however im having trouble with the border part.  any help is appreciated.

Limbs Part

int width = 800;
int height = 800;

int nTentacles = 10;

int nSegs = 30;
float totalLength = width/2;  
float downScaling = .9;
float baseLength;
float baseThickness = 10;
float maxdTheta = 1.5*(2*PI)/nSegs;
float maxdThetaVelPerStep = maxdTheta/40;
float maxThetaVel = maxdThetaVelPerStep*2;
float trickleVelScaling = nSegs*.003;

boolean centeredTentacles = true;
boolean drawSuckers = true;

color backgroundColor = color(255,255,255);
color tentacleColor = 0;
color suckerColor = #D1F6FA;
color suckerOutlineColor = 0;
float suckerScale = .8;


Tentacle[] tentacles;


void setup(){
 frameRate(30);
 smooth();
 size(width,height);
 
 tentacles = new Tentacle[nTentacles];
 for(int i=0; i<nTentacles; i++){
   if(centeredTentacles)
     tentacles[i] = new Tentacle(width/2, height/2, TWO_PI/nTentacles*i-PI/2);
   else
     tentacles[i] = new Tentacle(width/2+totalLength/1.5*cos(TWO_PI/nTentacles*i),
                                 height/2+totalLength/1.5*sin(TWO_PI/nTentacles*i),
                                 TWO_PI/nTentacles*i+PI);
 }
}

void draw(){
 blankScreen();  
 for(int i=0; i<nTentacles; i++){
   tentacles[i].drawTentacle();
   tentacles[i].wiggleTentacle();
 }
}

void blankScreen(){  
 fill(backgroundColor);
 noStroke();
 rect(0,0,width,height);
}

Tentacle Part


class Tentacle{    
 float x0,y0,theta0;
 float[] segLengths;
 float[] segThetas;
 
 Tentacle(float x0i, float y0i, float theta0i){
   x0 = x0i;
   y0 = y0i;
   theta0 = theta0i;
 
   baseLength = totalLength*(downScaling-1)/(pow(downScaling,nSegs)-1);
   
   segLengths = new float[nSegs];
   segThetas = new float[nSegs];
   for(int i=0; i<nSegs; i++){
     if(i==0)
       segLengths[i] = baseLength;
     else
       segLengths[i] = segLengths[i-1]*downScaling;
   }
 }

 void drawTentacle(){
   float x1 = width;
   float y1 = y0;
   float x2 = x0;
   float y2 = y0;  
   float totalTheta = theta0;
   for(int i=0; i<nSegs; i++){
     stroke(tentacleColor);
     strokeWeight(baseThickness*segLengths[i]/segLengths[0]);
     totalTheta+=segThetas[i];
     x2 = x1+segLengths[i]*cos(totalTheta);
     y2 = y1+segLengths[i]*sin(totalTheta);
     line(x1,y1,x2,y2);
   
     if(drawSuckers){
       fill(suckerColor);
       stroke(suckerOutlineColor);
       strokeWeight(0);
       ellipse((x1+x2)/2,(y1+y2)/2,
              baseThickness*segLengths[i]/segLengths[0]*suckerScale,
              baseThickness*segLengths[i]/segLengths[0]*suckerScale);

     }
     x1 = x2;
     y1 = y2;
   }
 }
 
 
 float[] segVelocities = new float[nSegs];
 
 void wiggleTentacle(){
   for(int i = 0; i<nSegs; i++){
     

     if(segThetas[i] <= -maxdTheta || segThetas[i] >= maxdTheta)
       segVelocities[i] = 0;
   }

   for(int i = nSegs-2; i>=0; i--){
     segVelocities[i] += segVelocities[i+1]*trickleVelScaling;
   }
   
 
   segVelocities[nSegs-10] += random(-maxdThetaVelPerStep,maxdThetaVelPerStep);
   

   int sign = 1;
   for(int i = 0; i<nSegs; i++){
     if(segThetas[i]>0 && segVelocities[i]>0){
       segVelocities[i] = min(segVelocities[i],
                              maxThetaVel*(1-segThetas[i]/maxdTheta));
     }
   if(segThetas[i]<0 && segVelocities[i]<0){
       segVelocities[i] = min(abs(segVelocities[i]),
                              maxThetaVel*(1-abs(segThetas[i])/maxdTheta));
       segVelocities[i] = -segVelocities[i];
     }
   }
   

   for(int i = 0; i<nSegs; i++){
     segThetas[i] = constrain(segThetas[i]+segVelocities[i],
                              -maxdTheta*(1-i/nSegs),
                              maxdTheta*(1-i/nSegs));
   }
 }
}